The wireless communication environment in a home or an office generally includes a number of independently developed radio access technologies and standards. These technologies were initially designed for target applications and they perform relatively well for these applications. In a typical home or office environment, an access to content (e.g., web, video, etc.) is provided to a broadband modem through the home-owner's IP backhaul connection. For instance, mobile services are provided through the cellular network, through either a macro cell or a femto cell located within the home or office. Wireless local area network (WLAN) access points (APs) provide data connectivity between computers, cell phones, laptops, printers, and other wireless stations using 802.11-based Wi-Fi technology.
Another communication medium currently being implemented in electronic equipment is near-field communication (NFC). The use of NFC interfaces in electronic equipment provides portable devices with functions similar to those of non-contact integrated circuit cards (e.g., radio frequency identification (RFID) cards). In addition, electronic equipment provided with NFC interfaces is typically capable of operating as radio frequency (RF) readers and/or writers to communicate with other NFC devices. A basic aspect of NFC is the use of electromagnetic waves in an RF range and the transmission of information contents is realized over a short distance only, for instance in a range of about several centimeters.
RFID technology is widely used in many areas such as public transportation services, object tracking systems and home management, and it is growing rapidly. It can handle the information from tags. The RFID application technology is currently integrated in one chip. 13.56 MHz RFID reader specification is based on the standard including ISO 14443 type-A, type-B, ISO 15693 and ISO 18000-3 standards. In NFC or an RFID application, a transmitter of a proximity coupling device (PCD), also known as a reader, writer or initiator, may use one of following three linear codes, followed by an amplitude modulation: (1) a modified-Miller code used for NFC type-A, (2) a non-return-to-zero (NRZ) code used in NFC type-B, and (3) a Manchester code used in NFC type-F.